Visual display systems, such as flight simulation systems, are commonly employed to train military, commercial and other personnel. Conventional visual display systems include one or more screens onto which a video image is projected by one or more projectors, such as light valve projectors or cathode ray tubes (CRTs). An operator views the projected video images and reacts in response thereto. Accordingly, the operator of the visual display system is also generally provided with a control panel and, in some instances, a joystick for providing input to the visual display system in response to the displayed video image. Thus, the operator can simulate the flight of an aircraft, for example, and can respond to the environment as depicted by the visual display.
In conventional flight simulation systems in which a full color video image is displayed, one projector, generally termed an RGB projector, is typically associated with each screen of the visual display system to project the red, green and blue color components of the video image on the associated screen. A typical RGB projector produces video images, each of which consist of a predetermined number of video lines, and each line of which consists of a predetermined number of picture elements, or pixels. For example, a conventional projector produces 1,024 video lines, each consisting of 1,280 pixels. In addition, the video images are produced at a predetermined frequency or frame rate, such as 30 or 60 hertz.
Conventional flight simulation systems include a variety of types and shapes of display screens on which the video image is displayed. For example, some flight simulation systems include a single flat display screen having a field of view which is generally positioned in front of the operator. These flight simulation systems generally require only a single RGB projector for projecting the video images upon the display screen. Thus, the design of flight simulation systems which include a single flat display screen is less complex than other types of flight simulation systems. However, the realism of such simulation systems is limited since the video images displayed on the single flat display screen generally do not accurately represent the out the window (OTW) view of the pilot of most aircraft who can also look laterally.
Another type of conventional flight simulation system which provides a more realistic visual image for the operator includes a spherically shaped dome structure on which the video image is projected. The operator is generally seated at a control station within the spherical dome such that the operator can view video images that are displayed in front of, beside of, above and, in some instances, behind the operator.
One exemplary flight simulation system which includes a partial dome having a generally spherical shape is disclosed in U.S. Pat. No. 4,634,384 which issued Jan. 6, 1987 to Fernando B. Neves et al. (hereinafter the "'384 patent"). As illustrated in the '384 patent, a spherical screen partially surrounds the operator. One or more display sources, such as Schlieren light valve projectors, are mounted above the operator on a front side of the screen for projecting the video images on the spherical display screen. The operator thereafter reacts to the displayed video images by actuating various controls to control the simulated flight of the aircraft.
While flight simulation systems which include spherical display screens provide a more realistic video image to the simulation operator, such flight simulation systems are generally physically large and complex. In addition, such flight simulation systems are generally both mechanically and electrically complex such that the flight simulation systems cannot be readily transported between locations in the field. Further, such flight simulation systems generally include a number of integrated display sources, such as light valve projectors or CRTs, which add to the complexity of the system.